Process of fabricating laminations



June 29, 1937. E, URTH 2,085,092

PROCESS OF FABRICATING LAMINATIOHS Filed Dec. 15, 1955 Enamel/7'19 punch bunch pres-5 Annealing Press Furnace za 1a Hg. 2. Fly. 5.

1o 29 27 I0 27 a0 1 i I l g 2 Patented... June 29, 1937 UNITED STATES PROCESS OF FABRICATING LAMINATIONS Ernest L. Furth, Pittsburgh, -Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 13, 1935, Serial No. 54,251

6 Claims.

steps requiring the handling of the laminations for each of the steps. In these processes, the 'expense of handling the material is large. It is also found that the strains set up in the material by handling are not uniform and that it I is not always possible to produce the same characteristics in a plurality of the laminations which have been subjected to similar heat treatments. An object of this invention is to provide a continuous process for fabricating laminations of magnetic material suitable for building electrical apparatus.

This invention, together with other and additional objects, will be better understood from the following description, when taken in conjunction with the accompanying drawing, in which Figure 1 is a schematic plan view of the apparatus employed in the process of this invention.

Fig. 2 is a plan view of the strip material from which the laminations are fabricated after it has been subjected to one of the steps of the process of this invention.

Fig. 3 is a plan View of the strip material after it has been subjected to another step of the process in the fabricating of the laminations in accordance with this invention, and

Figs; 4 and 5 are plan views illustrating the strip material after it has been subjected to certain of the steps employed in fabricating a modified fofm of the laminations.

In fabricating the laminatlons of magnetic material for use in electrical apparatus, care must be exercised in order to protect the laminations from strains which have a detrimental effeet on the magnetic properties of the material.

Referringto the drawing and particularly to Fig. 1 thereof, this invention is illustrated as applied to a continuous strip of magnetic material ill. 'In practice, the process of this invention is applied to the alloy comprising substantially 50% nickel, 50% iron with a small amount of manganese known by the trade under the trade mark Hipernik or a l silicon steel known under the trade mark Hypersil. This process is, however, applicable to any of the known magnetic steels.

As illustrated, the continuous strip H! is drawn from a roll H of the magnetic material to an enameling chamber l2 containing a; suitable enameling bath, such as water glass. In order to clean the surface of the strip before applying the enamel thereto, a set of brushes or rollers I3 are so disposed on the enameling chamber I2 that the strip ill moves between the rollers l3 before entering the enameling bath. After the strip is coated with the enamel, the enamel may be dried either by exposure to the atmosphere or by means of the application of suflicient heat applied in any suitable manner. The enamel coating on the surface of the strip acts as an insulating coating and further acts as a lubricant for the cutting tools when the laminatlons are out from the strip as hereinafter described.

Since the punching or cutting of the strip into the desired shape and size of the lamlnations sets up strains in the material which are detrimental to its magnetic properties, this inven tion provides for so cutting the material along predetermined lines so as to substantially form or outline the laminatlons prior to annealing the material.

As shown by Fig. 1 of the drawing, the enamele'd strip ill of the magnetic material moves from the enameling chamber 12 to a suitable means for punching, cutting or severing the material along predetermined lines. As illustrated, the means comprises a punch press 18, the action of which may be controlled in any suitable manner by the speed or movement of the continuous strip i as it passes through the punch press.

Fig. 2 of the drawing shows a portion of the strip I!) after it has been cut by the punch press 14. As shown, the shape of the laminations 15 has been outlined on the strip by cutting the-strip along the predetermined lines 18 to substantially cut out the laminations. The laminations l are held in position in the strip ill by the minor uncut portions I! that are not cut by the punch press 14. By cutting the strip in this manner, the laminations are partially severed from the strip and the strains of cutting the laminations are set up in the material before the material is annealed. The length and number of the uncut portions or supports]? will depend on the style and weight of the laminations 15. In addition to the cutting of the laminations along predetermined lines l6, the die of the punch press l4 cuts out or notches out. In moving from the punch press 22, the laminaa plurality of keyways I 8 in the strip, the purpose of which will be explained hereinafter.

By retaining the substantially cut out laminations supported in position in the strip by the uncut portions II, the laminations may be moved directly to the annealing furnace and subjected to a heat treatment to improve their magnetic properties and to release the strains set up by cutting the laminations.

In annealing the strip of magnetic material, the strip is subjected to a temperature of from 650 C. to 1200 C. T'he annealing cycle may be any of those known to the industry comprising a heating and predetermined cooling of the magnetic material. The cooling of the material may be accomplished either by moving the material through a cooling chamber (not shown) after it is annealed or where it is necessary to quickly quench the material, the quenching may be accomplished by moving the annealed strip directly into the air from the furnace l9 or the quenching may be accomplished by a suitable water or oil bath (not shown).

Where a controlled heating and cooling of the strip material is desired, the annealing furnace I 9 may be so constructed that the\temperature of the furnace may be controlled in a predetermined manner to provide predetermined annealing temperatures throughout the length of the furnace. This annealing develops the magnetic properties of the material and releases the strains set up in the laminations when out or punched by the punch press i4.

After being annealed, the strip material I0 with the laminations supported in position therein is drawn from the annealing furnace l9 to a second enameling chamber 20 containing a bath of water glass or other suitable enameling liquid. As on the device shown generally at l2, brushes 2| are provided on the enameling chamber 20 to clean the strip material before it enters the enameling bath.

When the strip material is annealed to develop its magnetic properties and anameled to provide insulation, it moves to a punch press 22 for cutting or severing the points of support I! of the laminations I5 held in position in the strip material III. The punch press22 is similar to the punch press I4, and is similarly controlled by the speed or movement of the strip ID. The punch press 22 is so set that when the keyway l8 cut into the strip ID by the punch press H is fitted therewith, it operates to cut the strip material, as shown in Fig. 3, along the predetermined lines 23 to cut the points of support I! and sever the laminations l5 from the strip.

The strains set up in the laminations by severing the laminations l5 from the strip material are negligible. This is because only a negligible portion of the material is affected when the portions supporting the laminations in the strip are tions ii are removed from the continuous strip of material I0 by any suitable means and the strip of scrap material remaining may be wound into the roll 26.

This invention may be employed in fabricating, laminations other than those suitable for use as the coreparts of transformers. Figs. 4 and 5 of the drawing show the strip I!) after it is subjected-to the cutting steps before and after the anneal respectively in fabricating a rotor punching. As illustrated, the rotor punching 21 is substantially cut out along predetermined 1 1. 65 28 by the action of the punch-press l4 prior to the annealing step. The rotor punching 21 is supported in position in the strip by the uncut supporting portions 29. After annealing and enameling the substantially cut out rotor punching 21, the finished punching may be completely severed from the strip [0 by cutting the strip 10 along predetermined lines 30 to cut the points of support 29 when the strip is drawn through the punch press 22.

By the process of this invention, it is evident that laminations of magnetic material suitable for building electrical apparatus may be fabricated without handling the material between each of the steps of cutt; 11g the laminations and annealing and enameling. Further, it is evident that each of the laminations receives the same treatment throughout the process so that the characteristics developed in the material will be uniform.

Although this invention has been described with reference to a particular process, it is evident that other and various modifications thereof are possible. Instead of the punch presses I4 and 22, described in this particular process, shears, slitters or simple tools for forming the cutting punches may be substituted. Further, although this invention has been described with reference to cutting particular designs of laminations along certain predetermined lines, it will be understood that other and various forms of the laminations may be fabricated. Where desired the enameling steps may be eliminated. This invention is, therefore, not to be restricted except insofar as is necessitated by the prior art and the scope of the appended claims.

I claim as my invention:

1. In a continuous process of fabricating laminations for electrical apparatus from a continuous strip of magnetic material, in combination, moving the strip through an enameling bath to provide an insulating coating on it, moving the insulated strip through means for cutting the strip along predetermined lines to substantially form the laminations, the laminations being maintained in position in the strip by predetermined uncut supporting portions, moving the strip through a furnace at a temperature sufficiently high to anneal it and moving the annealed strip through another means for cutting the said supporting portions to sever the annealed and insulated laminations from the strip.

2. In a continuous process of fabricating laminations for electrical apparatus from a continuous strip of magnetic material, in combination, moving the strip through an enameling bath to provide an insulating coating on it, moving the insulated strip through means for cutting the strip along predetermined lines to substantially form the laminations, the laminations being maintained in position in the strip by predetermined uncut supporting portions, moving the strip through a furnace at a temperature willciently high to anneal it, moving the annealed strip through another enameling bath to further insulate the strip material, and moving the annealed and insulated strip through another means for cutting the said supporting portions to sever the annealed and insulated laminations from the strip.

3. In a continuous process oi fabricating laminations for electrical apparatus from a continuous strip of magnetic material, in combination, moving the strip through means for cutting the strip along predetermined lines to substantially 75' form the laminations, the laminations being maintainedin position in the stripby' predetermined uncut supporting portions moving the strip through a furnace at a temperature sufiiciently high to anneal the strip, moving the annealed strip through an enameling bath to provide an insulating coating for the laminations, and moving the annealed and enameled strip through another of said means for cutting the said supporting portions to sever the annealed laminations from the strip.

v4. In a continuous process of fabricating laminations for electrical apparatus from a continuous strip of magnetic material, in combination,

.' moving the strip through an enameling bath to provide an insulating coating on it', moving the insulated strip through a punch press and operating the punch press to outline the shape of the laminations and partially sever them from the strip, moving the partially severed strip through a furnace to anneal the material, and then moving the partially severed and annealed strip of material through another punch press to complete the severing of the laminations from the annealed strip of material.

5. In a continuous processof fabricating laminations for electrical apparatus from a continuous strip of magnetic material, in combination, passing the strip through an enameling bath to provide an insulating coating on it, passing the insulated strip through means for outlining the shape of the laminations and partially severing them from the strip, passing the partially severed strip through a furnace to subject the strip to a temperature of between 650 C. and 1200 C.,

cooling the strip, and then passing the partially severed and heat-treated strip of material through another means to complete the severing of the laminations from the strip of material.

6. In a continuous process of fabricating laminations for electrical apparatus from a continuous strip of magnetic material, in combination, passing :the strip through an enameling bath to provide an insulating coating on it, passing the insulated strip through means for outlining the shape of the laminations and partially severing them' from the strip, passing the partially severed strip through a furnace to subject the strip to a temperature of between 650 C. and 1200 C., cooling the strip, passing the heat-treated strip of material through another enameling bath to further insulate the strip material, and then passing the partially severed, heat-treated and insulated strip of material through another means to complete the severing of the laminations from the strip of material.

ERNEST L. FUR'IH. 

